Difference between Functional Requirements and Non-Functional Requirements
Functional Requirements |
Non Functional Requirements |
---|---|
A functional requirement defines a system or its component. |
A non-functional requirement defines the quality attribute of a software system. |
It specifies “What should the software system do?” |
It places constraints on “How should the software system fulfill the functional requirements?” |
Functional requirement is specified by User. |
Non-functional requirement is specified by technical peoples e.g. Architect, Technical leaders and software developers. |
It is mandatory. |
It is not mandatory. |
It is captured in use case. |
It is captured as a quality attribute. |
Defined at a component level. |
Applied to a system as a whole. |
Helps you verify the functionality of the software. |
Helps you to verify the performance of the software. |
Functional Testing like System, Integration, End to End, API testing, etc are done. |
Non-Functional Testing like Performance, Stress, Usability, Security testing, etc are done. |
Usually easy to define. |
Usually more difficult to define. |
Example |
Example |
Functional vs Non Functional Requirements
Requirements analysis is a very critical process that enables the success of a system or software project to be assessed. Requirements are generally split into two types: Functional and Non-functional requirements.
Important Topics for Functional vs Non Functional Requirements
- Functional Requirements
- Non-Functional Requirements
- Extended Requirements
- Difference between Functional Requirements and Non-Functional Requirements: